Počvenno-landšaftnye uslovija severo-zapadnogo Prikaspija vo 2 tys. do n.ė.-1 tys. n.ė. Soil and landscape conditions in the north-western Caspian area in the 2nd millenium B.C.-1st millenium A.D. - Demkin, Vitalij Aleksandrovič (1993)